Rare-earth orthoferrites (RFeO3, R = La, Y) as next-generation electrode materials for high-performance supercapacitors

Abstract

This study addresses the synthesis and electrochemical assessment of nanocrystalline orthoferrites (RFeO₃, R = La and Y) synthesized via a sol–gel auto-combustion method. The synthesized orthoferrites were systematically characterized for their structural, morphological, and electrochemical properties. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed that both samples crystallized in a single-phase orthorhombic perovskite structure, with nanoscale domains. Upon their assessment as supercapacitor electrode materials, LaFeO₃ exhibited a remarkably high specific capacitance of 815.6 F g⁻¹ at 1.0 A g⁻¹, which is nearly twice that of YFeO₃. Furthermore, LaFeO₃ retained 88–90% of its initial capacitance after 10 000 galvanostatic charge–discharge cycles, demonstrating its exceptional cycling resilience. The superior electrochemical performance of LaFeO₃ is attributed to its electronic structure and optimized morphology and surface area, which facilitate effective ion diffusion and reversible redox reactions of Fe²⁺/Fe³⁺ at the electrode–electrolyte interface. These characteristics lead to enhanced charge storage kinetics and structural robustness during repeated cycling. This excellent electrochemical performance, combined with a cost-effective and scalable synthesis, demonstrated LaFeO₃ to be a promising electrode material for next-generation high-performance supercapacitor applications.